The use of touch-sensitive surfaces as input devices for computers and other electronic computing devices has increased significantly in recent years. Exemplary touch-sensitive surfaces include touch pads and touch screen displays. Such surfaces are widely used to manipulate user interface objects on a display. Typical manipulations include adjusting the position, size, and/or orientation of digital images, graphic objects, text, and other user interface objects. For example, a user may need to perform such manipulations on a digital image and/or a cropping mask rectangle for the digital image in an image editing application (e.g., Aperture or iPhoto from Apple Computer, Inc. of Cupertino, Calif.), a drawing application, a presentation application (e.g., Keynote from Apple Computer, Inc. of Cupertino, Calif.), a word processing application (e.g., Pages from Apple Computer, Inc. of Cupertino, Calif.), a website creation application (e.g., iWeb from Apple Computer, Inc. of Cupertino, Calif.), a disk authoring application (e.g., iDVD from Apple Computer, Inc. of Cupertino, Calif.), or a spreadsheet application (e.g., Numbers from Apple Computer, Inc. of Cupertino, Calif.).
But conventional methods for performing these manipulations are cumbersome and inefficient. For example, using a cursor to individually adjust multiple handles on multiple user interface objects (e.g., digital images and/or cropping mask rectangles) is tedious and creates a significant cognitive burden on a user. In addition, conventional methods take longer than necessary, thereby wasting energy. This latter consideration is particularly important in battery-operated devices.
Accordingly, there is a need for computing devices with faster, more efficient methods and interfaces for manipulating on-screen objects. Such methods and interfaces may complement or replace conventional methods for manipulating on-screen objects. Such methods and interfaces reduce the cognitive burden on a user and produce a more efficient human-machine interface. For battery-operated computing devices, such methods and interfaces conserve power and increase the time between battery charges.